Endless strip winding device



July 5, 1966 1- c s 3,259,332

ENDLESS STRIP WINDING DEVICE Filed Oct. 16, 1965 2 Sheets-Sheet llrwenlor Attorney July 5, 1966 J. H. FRANCIS 3,259,332

ENDLESS STRIP WINDING DEVICE Filed Oct. 16, 1963 2 Sheets-Sheet 2Attorney United States Patent 3,259,332 ENDLESS STRIP WINDING DEVICIEJohn Henry Francis, Honnslow, Middlesex, England, assignor toTechnicolor Corporation of America, Hollywood, Calif, a corporation ofMaine Filed Oct. 16, 1963, Ser. No. 316,707 Claims priority, applicationGreat Britain, Oct. 19, 1%2, 39,625/62 Claims. (Cl. 242-5519) Thisinvention relates to apparatus for the storage and/or utilization ofendless strips of flexible material of the kind in which an endlessstrip of material is coiled up into spiral form, a loose bight of stripextending between and joining the outer and inner convolutions of thespiral and constituting the active or effective part of the strip whichco-operates with utilization means. In most cases the strip is arecord-bearing strip such as a kinematograph film bearing a sequence ofimages or a sound record, either a photographic or magnetic soundrecord, or a combined kinematographic record and sound record, or suchas may be used to store signals or data for programming the operation ofprocesses or machinery. In use, such a strip is normally drawn out fromthe inner convolution, and the bight passes some form of utilizationmeans, such as a kinematographic intermittent feed device and gate, or asound head. The strip is fed back to and coiled upon the outside of thecoil thereof. The whole length of the strip may be repeatedly orcontinuously fed through the utilization means in the same directionwithout any need for rewinding it as a separate operation.

When tension is applied from the bight to the inner convolution in orderto draw out the strip from the coil, particularly if there is anytension applied to the end of the bight adjacent the outer convolutionof the coil or if there is significant friction between the convolutionsof the coil and any cheeks or the like between which the coil may bedisposed, there is a tendency for the outer convolutions of the coil tobe tightened upon the inner convolutions, coupled with a tendency forthe outer and inner diameters of the coil to contact, owing to what maybe termed the capstan effect. This entails increased friction betweenthe convolutions and increase of tension required to pull out the stripfrom the innermost convolution of the coil. If the coil is wound about acore, moreover, owing to the tendency for the coil to contract, asmentioned, the inner convolution may become rather securely clamped tothe core, so that it is practically difficult or even impossible to pullout the strip of the inner convolution into the bight. The effectsmentioned tend to be cumulative and to be much increased with increasein the number of convolutions of the coil.

The principal object of the present invention is to provide a storagedevice for endless strips of the kind referred to in which a build up intension of the strip in the various convolutions as the bight is drawnout from the inner convolution is reduced or, indeed, entirely obviated,so that the tightening of the outer convolutions of the coil upon thosewithin them is obviated and the capstan effect is substantially orwholly eliminated.

According to the present invention, in a storage and/ or utilizationapparatus of the kind set forth, the endless strip material is coiledupon a circular core which is rotated at an average peripheral speed notless than and preferably slightly greater than the average linear speedat which the strip is drawn from the inner convolution into the bight.Thus the strip tends to be extruded from the inner convolution into thebight so that the convolutions of the coil are substantially relieved oftension, friction be tween the convolutions is minimized and clamping ofthe inner convolution against the core is eliminated.

One general form of device according to the invention for storing anddelivering in a bight endless strip of flexible material of the kind setforth comprises a core upon which the endless strip, other than thebight, is coiled, with the bight extending from the inner to the outerconvolution, an endless movable traction surface arranged to receive thestrip in the bight and to move the strip substantially at its own speed,and means for moving the traction surface and the core at pre-determinedspeeds such that the average peripheral speed of the core is not lessthan and preferably appreciably greater than the surface speed of thetraction surface.

The traction surface will usually be a cylindrical surface of a drum,but it may be a continuous belt or even in some cases a sprocket, theteeth of which engage perforations in the strip. When the tractionsurface is that of a drum or a belt, it is preferably such as to providea high degree of friction between that surface and the strip so thatslippage between these two is minimized.

The part bearing the traction surface and the core are preferablyinterconnected with one another by a resilient connection permittingunder resilient constraint limited variations of their respectivespeeds, and one of them has a drive imparted to it, the other beingdriven therefrom through the resilient connection. In a preferredconstruction the traction surface is constituted by the periphery of acylindrical drum, which is coaxial with the core and is connectedthereto by a torsion spring so as to transmit torque from one to theother. In this case the diameter of the drum should exceed that of thecore. The necessary drive may. be applied to the drum or other tractionmeans frictionally through the strip itself, the bight of the latterbeing drawn out by other means such as a roller which, in the case of akinematograph film bearing a sound record, or in the case of separatekinematograph pictures and sound records, guides and controls the speedof the sound record past the sound track pick-up. This roller may bedriven. Alternatively, the necessary drive may be imparted to the drumthrough the strip by a friction roller bearing on the strip, andpressing it against the drum.

For the better understanding of the invention, one particular form ofprojector film casette for 8 millimetre kinematograph film having amagnetic sound track along its edge outside the perforations will now bedescribed by way of example only with reference to the accompanyingdrawings in which:

FIG. 1 is a side elevation of one side of a casette according to theinvention with part of the cover removed;

FIG. 2 is a side elevation of the other side of the casette, with thefilm omitted,

FIG. 3 is a section on the line III-III of FIG. 1;

FIG. 4 is a front elevation;

FIG. 5 is a section on the line V-V of FIG. 1 with the film omitted; and

FIG. 6 is a schematic perspective view of the interior of the casette,illustrating the run of the Referring now to the accompanying drawings,the casette proper comprises a shallow cylindrical tray 10 having at oneside an extension 11 which may conveniently be of rectangular shape. Acentral spindle 12 is fixed to the base 13 of the tray coaxial with thecylindrical wall 14- thereof. Preferably a loose thin circular disc 15of diameter slightly less than the internal diameter of the tray 10 isjournalled freely upon the spindle 12, upon which is also jo-urnalled acircular core 16 overlying the disc 15. The disc 15 may be slightlyspaced from the base 13 by a stud 42 fixed to the base, so

as to preclude adhesion of the disc 15 to the base 13. A coil 32 of film18 is wound upon the core 16 with its inner end protruding at theside ofthe core. The peripheral surface of the core 16 is preferably slightlyconical in order to facilitate the drawing out of the bight of film fromthe inner convolutions 17 of film 18 that will embrace it. An annulardisc 19, the diameter of the aperture of which is greater than thediameter of the core 16, is laid over the coil, the inner end of thefilm passing through a gap between the core 16 and the inner peripheryof the disc 13. The inner edge 21 of the annular disc 19 is receivedover a short part of its length in a groove 20 formed in the peripheryof the core 16. The inner edge 21 of the disc 19 is further guided bybeing engaged beneath flanges 22 and 23 of rollers 24 and 25 that arefreely journalled upon spindles 26 and 27 fixed to a cover 28 of thetray 10. The core 16 is hollow and is provided with an eccentricallydisposed peg 29.

A cylindrical drum 30, constituting what has been termed an endlessmovable traction member, is freely journalled upon the spindle 12. Theperipheral surface of this drum 30 is covered by high-friction material31, such as rubber. The start of the bight of the film 18 is led aroundpart of the periphery of the drum 30 and passes from the innerconvolution of the coil 32 of film 18 wound about the core 16 inside butin contact with the roller 24 and from the periphery of the endlessmovable traction member or drum 30 outside the roller 25. A spiraltorsion spring 33 has one end engaged with the drum 30 near its axis andits other end engaged with the eccentrically disposed peg 29 of the core16.

The necessary drive is imparted to the drum 30 through the film 18. Tothis end an additional drum 34 is freely journalled upon a spindle 35fixed to the cover 28 of the casette. One or more friction drivingrollers, 35 (see FIG. 6) forming part of the camera, projector or otherutilization apparatus, bears on the outside of the film 18 against thedrum 34 so as to apply pressure to the film 18 and thus to rotate thedrum 34. A slot 36 (or slots) is provided in the edge of the cover 28 ofthe casette to admit at least part of the periphery of the drivingroller or rollers 35 for this purpose.

The additional drum 34 referred to may be that upon the surface of whichthe film is presented to a soundtrack pick-up 37. For this purpose theadditional drum 34 may be driven at a regulated speed.

As illustrated in FIG. 6, from the nip of the driving roller 35 againstthe additional drum 34 the film 18 passes into the rectangular extension11 of the casette through a passage 38 when it is formed into a loop 43.It then passes a spring gate 44 that forms part of the boundary of theextension 11. Thence it is formed into another loop 39 and passes backto the outer convolution of the coil 32 within the casette through achannel 40. The casette is provided with a cover 28. The casette, coverand disc are preferably made of a plastic material which has a lowcoefficient of friction.

In operation, when the casette is in an operative projector, the film 18is drawn from the inner convolution 17 of the coil 32 due to the driveimparted thereto by the friction-driving roller 35 of the projector. Thedrum 30 is consequently rotated by a drive imparted through the film 18.At the same time a drive at the same average angular speed is impartedto the core 16 through the spiral torsion spring 33. However, since thediameter of the core 16 is slightly greater than that of the drum 30,the peripheral speed of the core 16 is slightly higher than that of thedrum. Thus the film of the inner convolution 17 of the coil 32 isrelieved of tension, and the film 18 is fed into the bight undercompression rather than under tension. The convolutions of the coil 32of film 18 are thus relieved of tension, so that they may slide freelyupon one another.

It will be appreciated" that one particular form of casette inaccordance with the invention has been described with reference to andillustrated in the accompanying drawings by way of example only, andthat many modifications may be made without departing from the scope ofthe invention, as defined by the appended claims.

What is claimed is:

1. Apparatus for storing and feeding an endless strip formed in a coilwith a bight extending between the inner convolution and the outerconvolution of the coil comprising a cylindrical core on which the stripcoil is supported, a drum engaging the bight, means mounting said coreand drum coaxially and rotatively, and a spring coupling yieldinglyconnecting the core and drum, whereby, when the strip is drawn from thecoil, the drum is rotated by engagement with the strip and drives thecore through said spring coupling, thereby to prevent the inner turns ofthe strip coil from clamping on said core.

2. Apparatus according to claim 1 wherein the external diameter of thecore is greater than that of the drum.

3. Apparatus for storing and feeding an endless strip formed in a coilwith a bight extending between the inner convolution and the outerconvolution of the coil comprising a cylindrical core on which the stripcoil is supported, drive means for drawing the bight from the core, adrum engaging the bight, means mounting said core and drum coaxially androtatively, and a spring coupling yieldingly connecting the core anddrum, whereby, when the strip is drawn from the coil, the drum isrotated by engagement with the strip and drives the core through .saidspring coupling, thereby to prevent the inner turns of the strip coilfrom clamping on said core.

4. Apparatus for storing and feeding an endless strip formed in a coilwith a bight comprising a cylindrical core roll for supporting the stripcoil, drive means for drawing the bight from the core, an idler devicehaving an endless orbitting friction surface for tractiona'lly engagingthe bight intermediate the core and drive means whereby said surface isorbitted by tractional engagement with the bight as it is drawn by saiddrive member, and connecting means including a spring coupling betweensaid core roll and idler device for driving said core roll at an averageperipheral speed greater than that of said surface, thereby to preventthe inner turns of the strip coil from clamping on said core.

5. Apparatus according to claim 4 wherein said idler device is driven byfrictional engagement of the strip with said friction surface.

References Cited by the Examiner UNITED STATES PATENTS 2,031,079 2/1936Streyckmans 242-5519 2,781,689 2/1957 Heyer 242-5518 X 3,149,207 9/1964Maxey 242 5s.19 X 3,150,841 9/1964 Stevens 242-5519 OTHER REFERENCESGerman printed publication 1,020,190 (KL 42gl8), October 1957, Honolka.

MERVIN STEIN, Primary Examiner.

B. S. TAYLOR, Assistant Examiner.

1. APPARATUS FOR STORING AND FEEDING AN ENDLESS STRIP FORMED IN A COILWITH A BRIGHT EXTENDING BETWEEN THE INNER CONVOLUTION AND THE OUTERCONVOLUTION OF THE COIL COMPRISING A CYLINDRICAL CORE ON WHICHTHE STRIPCOIL IS SUPPORTED, A DRUM ENGAGING THE BIGHT, MEANS MOUNTING SAID COREAND DRUM COAXIALLY AND ROTATABLY, AND A SPRING COUPLING YIELDINGLYCONNECTING THE CORE AND DRUM, WHEREBY, WHEN THE STRIP IS DRAWN FROM THECOIL, THE DRUM IS ROTATED BY ENGAGEMENT WITH THE STRIP AND DRIVES THECORE THROUGH SAID SPRING COUPLING, THEREBY TO PREVENT THE INNER TURNS OFTHE STRIP COIL FROM CLAMPING ON SAID CORE.